firing right next to enemy

I've been searching around on the forum and on google, and am not having much luck. I'm working on a 4 player local multiplayer arena battle type game where you throw boomerangs at each other. I have a powerup that allows you to shoot fireballs. When I'm standing a distance away from an enemy the fireball takes energy from the opponents energy bar as it should, but when I'm standing next to the enemy, the fireball explodes, but does not take energy away. I have it set up so that on collision it takes the energy bar down, spawns the explosion sprite and destroys the fireball. Any ideas?

You can try colision OR OVERLAPING.

Thanks for your reply! I tried overlapping and didn't have any luck. I cloned my explosion and put each explosion with the different players bullet families and this seems to be a step in the right direction.